Many of today's printed circuit boards are tested during manufacture with automated test equipment having fixtures that hold the printed circuit boards in position while test probe pins are brought into contact with the boards at pre-determined test points. Upon contacting a board, the test probe pins each exert a force on the printed circuit board. For a board including a ball-grid-array device, numerous test probe pins must necessarily be employed to rapidly test the solder joints of the ball-grid-array device footprint. In order to resist the forces exerted by the test probe pins on one side of the board, a number of pushing rods are, typically, brought into contact with the other side of the board to apply counterbalance forces to the board.
Unfortunately, the ever-shrinking size and density of today's printed circuit boards and the inherent lack of unpopulated areas on such boards makes it increasingly difficult to apply counterbalance forces at appropriate locations necessary to offset the forces exerted on the printed circuit boards by the test probe pins. For those boards where it is not possible to apply counterbalance forces of sufficient magnitude at appropriate locations, imbalances in the forces applied to the boards by the test probe pins and pushing rods often cause solder joints in the area of a ball-grid-array device footprint to crack or open. To make matters worse, the layering of traces beneath a ball-grid-array device footprint in combination with the forces exerted by the test probe pins may enhance the possibility that board warpage may occur in and around the ball-grid-array device footprint. In turn, such board warpage may worsen the severity of any solder joint cracks caused by imbalance in the forces applied to such boards. What is needed, therefore, are methods and apparatuses for improving ball-grid-array solder joint reliability.